PARK CITY -- A beautiful, densely textured elegy for outlaw lovers separated by their own misdeeds, Ain’t Them Bodies Saints will serve most decisively to put director-writer David Lowery on the map as one of the foremost young standard bearers of the Malick and Altman schools of impressionistic mood-drenched cinema. This poetically told Texas crime saga is deeply and, to be honest, naively sentimental at its core, which creates something of a drain on its seriousness. But it’s a constant pleasure to watch and listen to, and stars Rooney Mara and Casey Affleck both have some rewarding strong scenes. To be sure, this is an out-and-out art film, one that looks to enjoy a measure of success on the festival circuit and in specialized release.

Lowery is a Texas-based filmmaker whose 2000 feature Lullaby went unnoticed and whose equally little-seen 2009 St. Nick revolved around two young kids who hide out in an abandoned house in the woods. Saints essentially begins with a messy shoot-out in just such an isolated shack, after which the criminal team of Bob Muldoon (Affleck) and Ruth Guthrie (Mara) are led off, with Bob destined for prison and the pregnant Ruth let go.

Set in the Texas hill country, probably in the very early 1970s based on the models of cars, the film immediately evokes a number of sympathetic outlaw classics that were made around that time in the wake of Bonnie and Clyde, specifically Malick’s Badlands and Altman’s McCabe & Mrs. Miller and Thieves Like Us. Far more attention is given to the couple’s intense bond than to clarifying the nature of what just went down; piecing together tiny snippets of information discreetly released here and there, it would seem that a robbery led to a police raid for which Bob took the rap for a cop actually shot by Ruth. Thereafter, Ruth and her baby girl, Sylvie, are installed in a comfortable house in the small Texas town of Meridian by an older gentleman named Skerritt (an excellent Keith Carradine, in a nod to Thieves and McCabe), whose relationship with the others in the story remains mysterious.

Lowery might parcel out key plot elements with great reluctance, but he manages to keep things interesting and even moderately gripping, partly because of the managed uncertainty over where everyone stands in relation to others. When it’s learned that Bob finally has succeeded, in his sixth attempt, to escape from prison, the natural expectation is that he’ll try to come for Ruth and to see his daughter, who’s now nearly 4, for the first time.

For her part, Ruth, who’s living a very low-key life next door to Skerritt, is shadowed by local cop Patrick (Ben Foster), a shy but persistent fellow who might be hoping that he’ll be the one Ruth turns to if something ever happens to Bob. Eventually, three obvious bad guys roll into town, but their affiliations and intentions remain disturbingly unclear for a long spell.

It all inevitably ends in gunplay and a measure of tragedy -- but of the kind that literally and figuratively bleeds into the history and mythology of the West.

This sort of fate has been idealized, poeticized, beautified and canonized countless times before in all manner of popular art forms, and Lowery buys into its lyric potential wholeheartedly.

But the writer-director simplifies and reduces Bob’s nature to that of a dreamer who imagines some fantasy land where he and his family can somehow exist apart from real life and consequences. Many similar doomed characters have expressed such dippy hopes in the past and sort of gotten away with it, but the “somewhere there’s a place for us” mentality outlives its welcome here, perhaps partially due to our ever-smaller world and also to the much grittier crime films that have followed since the 1970s models Saints so clearly emulates.

But that said, and for all its derivative poetics -- as many exteriors as possible were shot during or just after magic hour, a la Malick -- the film is a lovely thing to experience and possesses a measure of real power. Emerging cinematographer Bradford Young does his most impressive work yet, combining with Lowery, production designer Jade Healy and costume designer Malgosia Turzanska to deliver a kind of timeless look that feels equal parts Old West, Depression-era Texas and the slow-to-arrive modern age.

On top of this is an emphatically original score by Daniel Hart that employs an enormous variety of unusual motifs that impressively coalesce into a memorable whole that doesn’t use typical country or Southern music as a crutch.

Having played a really, really bad Texas bad guy in The Killer Inside Me three years ago, Affleck delivers a milder variation on one here, to stronger effect; one monologue he delivers to himself in a mirror is particularly striking. Pretty quiet through most of the film, Mara has a gravitas that makes her rewarding to watch no matter what, or how little, she’s doing. Foster is at his most subdued, and it’s a real pleasure to see Carradine again in a nice, if ambiguous, role.